Radial transducer structure



RADIAL TRANSDUCER STRUCTURE Filed March 26, 1951 INVENTORS CARL H. STEE/VSTRUP 6. J FALK BY X ATTORNEY Patented June 22, 1954 2,682,041 RADIAL TRANSDUCER STRUCTURE Carl H. Steenstrup,

Falk, Scotia,

N. Y., assi ments, to the United S resented by the Secret Schenectady, and Charles J.

gnors, by mesne assigntates of America as repary of the Navy Application March 26, 1951, Serial No. 217,443

1 Claim.

The present invention relates to improvements in transducers and more specifically to a radial underwater electroacoustic transducer.

An important object of the invention is to provide a transducer assembly adapted to transmit or receive acoustic energy radially but not longitudinally.

Another object of the invention is the provision of a transducer assembly adapted to withstand high external pressure.

A further object is to provide a transducer having it parts constructed and arranged for easy assembly.

A still further object is the provision of an improved watertight transducer assembly.

Other objects and advantages of the invention will become apparent during the course of the following detailed description, taken in connection with the accompanying drawing forming a part of this specification and in which drawing:

Fig. 1 is an end elevational view of the radial transducer.

Fig. 2 is a central longitudinal sectional view of the transducer assembly taken substantially on the line 22 of Fig. 1.

In the drawing, which for the purpose of illustration shows only a preferred embodiment of the invention and wherein similar reference characters denote corresponding parts throughout the views, the numeral I generally designates the transducer assembly comprising a hollow cylindrical acoustic rubber window II having its circumferential marginal edge portions l2, l3 mounted in suitably rabbeted rigid annular supports I4, I5.

These annular supports Id, l5 are so rabbeted as to provide inside telescopic walls I6, I! and beveled end-abutting walls l8, l9 that are bonded to the annular window margins as by cyclewelding or cementing.

Afiixed to one window support I 4 as by cap screws is a circular end cap 2i forming a watertight seal at one end of the transducer assembly.

Coaxially disposed within the hollow cylindrical window II is a rigid hollow cylindrical cuplike core 22 having its closed end wall 23 afiixed to the end cap 2| by internal cap screws 24 so as to reduce the possibility of leakage into the transducer assembly. The external diameter of this core is less than the inmrnal diameter of the hollow cylindrical window so as to provide an annular transducer space divided by a rigid electrically insulative annular radial load bearing wall 25 adapted to support the window at its transverse central portion against external pressure. Occupying the annular transducer space on opposite sides of the bearing wall 25 are two annular transducer elements 26, 21, preferably of the magnetostrictive type. These transducer elements 26, 21 include leads 23-3! extending through slots 32, 33 in the core 22 and connected to an electrically insulative terminal board 34 within the core.

Aifixed to the window support H: as by cap screws 35 is a circular end cap 36 including an axial packing gland 31 adapted to provide a Watertight seal for a suitable lead-in cable (not shown). The opposite end portions of the core 22 are fitted in circular coaxial recesses 38, 39 in the interior sides of the end caps 21, 36 thus providing a strong joint. The rigid metal parts of the transducer assembly including the core 22 are preferably formed of a non-magnetic material such as aluminum. Accordingly the metal core 22 forms an electrical shield for the transducer leads and acts to prevent longitudinal as well as radial compression of the transducer assembly due to high pressure.

Compressed in suitable grooves in the end caps 2|, 36 are packings such as O-rings 40, 4| insuring watertightness of the joints between the end caps and the Window supports [4, [5. The gland 31 is also grooved to receive a packing such as an O-ring 42 to prevent ingress of water around the gland.

In operation, acoustic energy is radially transmitted to and received from the transducer elements 26, 21 by the cylindrical acoustic window while the transmission and reception of acoustic energy axially of the assembly is blocked by the rigid end caps 2|, 36. The annular partition wall 25 between the double row of transducers reinforce the window so that it can withstand high pressure on its outside surface. If more than two rows of transducer elements are provided, a reinforcing partition wall may be interposed between each adjacent pair of transducer rows.

In assembling the transducer, it is convenient to reach inside through the end cap openings in the window supports l4, l5 in order to cycleweld or cement the transducer elements 26, 27 to the acoustic window I I.

Various changes may be made in the form of invention herein shown and described without departing from the spirit of the invention or the scope of the following claim.

What is claimed is:

A radial transducer comprising a hollow cylindrical shell of a material chosen for its ability communicating with the interior of said core, said to transmit acoustic energy, first and second rigid last-mentioned plug portion having an inside annular support having flange portions and surface provided with an annular recess receiving sleeve portions in respective end-abutting and said cylindrical core at its end opposite said inside-telescopic engagement with opposite end 5 closed end wall, means releasably afiixing said portions of said acoustic shell, said shell being last-mentioned plug portion to said core, said bonded to said annular supports at said fiangecore being smaller in diameter than the inside and sleeve-engaging portions, a first rigid end diameter of said shell whereby an annular space cap having a marginal flange portion releasably is defined between said core, shell and end caps,

afiixed to said first annular support and a cylin- 1 an annular transducer element occupying said drical plug portion telescopically fitting within space, a packing gland releasably affixed to said said first support, said plug portion having an second end cap in watertight sealing relation to inside surface provided with a central recess, a said opening, and leads extending through said rigid hollow cylindrical cup-like core axially dispacking gland and hollow core to said transducer posed within the shell and having a closed end element. wall fitting within said recess and releasably fastened to said first end cap, a second rigid end cap References Cited in the file of this patent having a marginal flange portion releasably af- UN STATES PATENTS fixed to said second annular support and a cylin- Number Name Date drical plug portion telescopically fitting with said 20 2 405 605 Goodaie Aug 13 1946 second support and provided with an opening July 19.50 

